Firearm



Jan. 27, 1970 E. ROHR 3,491,650

FIRE ARM Filed Aug. 15. 1967 2 Sheets-Sheet 1 "I! III,

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FIRE ARM Filed Aug. 15, 1967 2 Sheets-Sheet 2 Fig. 4

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Edwin Kohll United States Patent 3,491,650 FIREARM Edwin Rohr,Wettingen, Switzerland, assignor to Hammerli AG., Switzerland, acorporation of Switzerland Filed Aug. 15, 1967, Ser. No. 660,743 Claimspriority, application Switzerland, Aug. 18, 1966, 12,046/ 66 Int. Cl.F41c 3/00 US. Cl. 89-194 Claims ABSTRACT OF THE DISCLOSURE A fire-armhaving a breech block which is driven rearwardly under the explosiveforce of a fired cartridge and a recoil spring returning the breechblock into the firing position and in particular a piston. To reduce therecoil effect and to avoid the tendency of the free end of the barrel tosweep upward as a consequence of the recoil a compensating mass isprovided in the fire-arm which is movable substantially parallel to thebarrel and which has a mass corresponding substantially to that of thebreech block. Means are provided for transmitting to the mass member aforce impulse corresponding to the force impulse received by the breechblock when firing a cartridge to impart to the mass member a movementcorresponding to and coinciding with, respectively, the movement of thebreech block but having an opposite direction.

BACKGROUND OF THE INVENTION Present day hand fire-arms, i.e. pistolshave a very intensive recoil. This recoil has the effect of generallythrowing the barrel out of alignment with the target, e.g. of swingingthe free end of the barrel upwards and to the left if the pistol isgripped with the right hand. The strong recoil is due, on the one hand,to the gas pressure necessary for moving the breech block back whileejecting the fired cartridge and for tensioning the recoil spring whichlatter returns the breech block into the firing position while a newcartridge is fed into the cartridge chamber. On the other hand, highmuzzle velocities are required to obtain the necessary accuracy.

As an example showing the disadvantageous effect of high recoil, thecase of the Olympic rapid fire program may be taken. Here five shotsmust be fired within four seconds on targets yards away. The targets arespaced two and a half feet apart and each shot must be on a differenttarget. In view of the high rate of fire, little time remains for aimingand it is time consuming if the barrel must not only be swung sidewiseto find the new target but connected downwardly to return the barrel tothe correct height.

Attempts have already been made at reducing the recoil and particularlyat avoiding the upward thrust of the barrel produced thereby. In thiscontext it should be noted that the method attaching additional weightsto the pistol to reduce the upward movement of the barrel is notfeasible since in many instances the total weight as well as thedimensions of the pistol are limited. It has been proposed to provideone or more gas escape openings at the upper side of the barrelcommunicating with the bore in front of the cartridge chamber. However,it was found that the resulting reaction force on the barrel isinsuflicient to counteract the upward thrust resulting from the recoil.It should be noted that the quantity of gas available for producing thereaction force is limited since it causes a reduction in muzzle velocitytending to impair the accuracy of the weapon.

3,491,650 Patented Jan. 27, 1970 SUMMARY OF THE INVENTION Accordingly,it is a primary object of the present invention to provide an improvedfire-arm which has a reduced recoil.

Another significant object of the present invention is the provision ofan improved fire-arm which reduces the tendency of the barrel to swingupwardly during recoil upon the firing of a cartridge.

A further noteworthy object of the present invention relates to animproved pistol of the type used for Olympic shooting events whichfacilitates aiming and permits rapid fire.

Still another object of the present invention is the provision of animproved pistol which, while being of compact construction and having arelatively small weight, avoids high gas pressure losses and significantreduction in muzzle velocity in order to reduce recoil.

Now, in order to achieve these and still further objects of theinvention which will become more readily apparent as the descriptionproceeds, the fire-arm according to the invention is equipped with abarrel supported by a frame and having a cartridge chamber at one end. Abreech block is movable on said frame toward and away from the cartridgechamber end of the barrel, a recoil spring urging said breech blocktoward said cartridge chamber end into a closed position while the gaspressure of a fired cartridge moves said breech block away from saidcartridge chamber end while compressing said recoil spring. According toone significant aspect of the invention a movable compensating massmember is arranged adjacent the barrel, such mass member having a masscorresponding to that of the breech block. Means are provided to impartto the mass member a movement substantially equal to that of the breechblock and simultaneously therewith but in an opposite direction as aresult of the gas pressure of a fired cartridge. A return spring acts onthe mass member to return the latter at the end of said movement.

Due to the movement of the mass member upon firing of a cartridge, therecoil movement of the breech block is substantially compensated for sothat the tendency of the barrel to swing out of alignment with thetarget is reduced or avoided.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood, and objects other than those set forth above, will becomeapparent, when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexeddrawings depicting three exemplary embodiments of the inventive fire-armin the form of a rapid fire pistol for target contests, and wherein:

FIGURE 1 schematically illustrates in vertical section a pistol inaccordance with a first embodiment of the invention;

FIGURE 2 illustrates the barrel of the pistol depicted in FIGURE 1 in aplan view and partly in section;

FIGURE 3 is a fragmentary elevational view of the pistol with the breechblock being in the rearward end position;

FIGURE 4 illustrates in section a fragmentary view of a pistol barrel inaccordance with a second embodiment of the invention;

FIGURE 5 is a representation corresponding to FIG- URE 4 in anotherposition of the parts of the barrel; and

FIGURE 6 shows in vertical section a third embodiment of a pistol.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGURE 1 reference numeral1 designates the cartridge chamber of a pistol barrel generallyindicated at 27. Numeral 2 indicates a breech block movable between aforward position, shown in FIGURE 1, in which the cartridge chamber 1 isclosed and a rearward posi tion, shown in FIGURE 3, in which thecartridge chamber is accessible for feeding a cartridge into thecartridge chamber or for ejecting an empty cartridge therefrom. Framemember 28 forming a pistol grip and having secured thereto the barrel27, contains a cock mechanism comprising a cock 3 pivotably supported inframe member 28, a push rod 36 engaging cock 3 and being biased by acock spring 4 and a pivotable cock release member 6 engagable with aratchet tooth 5 on cock 3 under the influence of a leaf spring 35.Numeral 32 indicates a trigger arranged within a trigger guard 30 andpivotably secured to frame member 28 at 34. A trigger rod 33interconnects trigger 32 with trigger release member 6 to disengage thelatter from ratchet tooth 5 0n cock 3 and permit the latter to swing inclockwise direction under the influence of cock spring 4 when trigger 32is actuated.

Arranged within breech block 2 for movement therewith is a lock member26 movably supporting firing pin 25, which lies in the path of cock 3when the latter pivots in clockwise direction.

The breech block 2 is normally held in closed position by a recoilspring 21 arranged in frame member 28 adjacent barrel 27 and parallelthereto. To this end, recoil spring 21 which is guided on a spring pin31, abuts with its one end against the frame whereas the other end actson an extension 2 of breech block 2. Under the effect of the gaspressure developed by a fired cartridge, the breech block 2 is thrownbackwards against the action of recoil spring 21, thereby compressingthe latter. During such recoil movement of the breech block or whilebeing manually drawn back, firing pin 25 and lock member 26 abut againstcock 3 and rotate the latter in anticlockwise direction, therebydisplacing push rod 36 downward and compressing cock spring 4. When cock3 has reached the position indicated in FIGURE 1, lock release member 6engages cock 3 and retains the mechanism in cocked position if thetrigger 32 has been previously released. The recoil movement of breechblock 2 is limited by an abutment 29 situated in the path of extension2' (FIGURE 3). During its forward move ment under the influence ofspring 21, breech block 2 engages a new cartridge from magazine 23arranged in the pistol butt or grip of frame 2 8. Such cartridge is fedinto the cartridge chamber upon completion of the return movement ofbreech block 2 into the closed position. The pistol is therefore readyfor firing. The pistol so far described is conventional and consequentlyits operation will be readily understood by those skilled in the art.

In accordance with the invention, the pistol is provided with means forreducing recoil in the form of a movable compensating mass member 8.With further reference to FIGURE 1 it will be seen that compensatingmass member 8 which has the form of a piston is slidably arranged in acylinder 16 extending beneath barrel 27 and parallel thereto and beingsecured to frame member 28. At its forward end, cylinder 16 is closed011? by a threaded plug having an air vent therein. A return spring 9arranged in cylinder 16 and having one end resting on plug 10 engageswith its other end piston 8 and tends to maintain the latter in therearward end position indicated in FIGURE 1. As will be seen fromFIGURES 1 and 2, transmission means in the form of two bleed channels 7are connected to the rearward end of cylinder 16 and communicate eachwith a bleed bore 17 provided in the barrel 27 forward of the cartridge91 2.11. 1 l but closely adjacent thereto.

It will be understood that as a cartridge is fired in cartridge chamber1 of the barrel by the impact of cock 3 on firing pin 25, gas pressureis developed in the barrel accelerating the bullet to muzzle velocity.On the other hand, back pressure is exerted onto the empty shell so thatthe latter drives the breech block rearward. Due to the bleed bores 17,gas pressure is also transmitted to the cylinder 16 by way of channelsor tubes 7 and such gas pressure exerts a force upon the piston 8 toaccelerate the latter against the action of return spring 9. The mass ofthe piston 8 is chosen so as to substantially correspond to the mass ofthe breech block and by suitably dimensioning the bleed bores withregard to their cross section the piston which forms the compensatingmass will carry out a movement substantially counteracting the recoileffect, at least to the extent transmitted by the breech block. It willbe noted that cylinder 16 is provided with an opening or slot 22, whichpermits escape of the expanded gas when the piston '8 hits the plug atthe end of its forward movement.

Reference is now made to FIGURES 4 and 5 showing a further preferredembodiment. For the sake of clarity, the conventional parts of thepistol, which may have the construction described with reference toFIGURES 1, 2 and 3 are omitted. Again, reference numeral 28 indicatesthe :frame member receiving the rearward or cartridge chamber end ofbarrel 27. An annular mass member 12 is slidably arranged on barrel 27and surrounds the latter. Movement of the mass member 12 is limited onthe one hand by frame member 28 and on the other hand by an abutmentring 13 seated on the forward or muzzle end of the barrel. The barrel isfurther surrounded by a compression spring 14 having one end bearingagainst the abutment ring 13, whereas the other end of such spring actsagainst the mass member and tends to hold the latter in abuttingrelation with the frame member 28 as indicated in FIGURE 4.

A plurality of axially extending bores 18, forming gas chambers isprovided in the mass member 12. In the rearward position of such memberbores 18 are engaged by the ends of axially extending transmission meansin the form of tubes 19 having their other ends seated in frame member28 and communicating with the bore of the barrel forward of thecartridge chamber 1 by way of bleed openings 20.

Again, when cartridge in chamber 1 is fired a portion of the explosivegas will bleed through opening 20 and the pressure of the gas will betransmitted to the annular mass member through the tubes 19 and thebores 18. Consequently, forward movement will be imparted to mass member12 to counteract the effect of the rearward movement of the breechblock, as has been described in connection with FIGURES 1 to 3. Duringthe forward movement spring 14 will be compressed. The explosive gas mayescape as soon as the bores 18 have liberated the forward ends of tubes19. Spring 14 subsequently returns mass member 12 from the forwardposition shown in FIGURE 5 to the rearward position of FIGURE 4.

While in the embodiments so far described, movement is transmitted tothe mass member directly from the gas pressure developed by thecartridge, it is also possible to transmit such movement from the breechblock, i.e. from a mechanical part moved by such gas pressure and anembodiment of this type is illustrated in FIG- URE 6.

It will be noted that breech block 2 is slidably guided in frame member28 which supports the barrel 27. A compensating mass member 42 in theform of a slide is arranged below breech block and barrel in a recess 40of frame 28. A return spring 43 arranged in recess 40 tends to hold massmember or slide 42 in its rearward position as shown in FIGURE 6. Slide42 is provided with a rearwardly extending tooth rack and a gear wheel37 rotatably supported in frame 28 meshes with such rack. On the otherhand, gear wheel 37 is engaged by a tooth rack 44 provided on breechblock 2.

Consequently, when breech block 2 is driven rearward upon firing of acartridge, it rotates gear wheel 37 and the latter drives the slide 42forward at a velocity corresponding to that of the breech block. Therebythe recoil effect of the breech block is effectively compensated. Returnspring 43 returns slide 42 into the rearward position.

Tests made with pistols constructed in accordance with the inventionhave shown good results with respect to the reduction of the recoileffect.

While there is shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto, but may be otherwise variously embodied and practicedwithin the scope of the following claims.

What is claimed is:

1. A fire-arm comprising, in combination,

(a) a frame member;

(b) a barrel supported by said frame member and having a cartridgechamber end;

(c) a breech block arranged for reciprocable movement towards and awayfrom said cartridge chamber end of said barrel;

(d) a recoil spring cooperating with said breech block for urging thelatter toward said cartridge chamber end, said breech block being drivenrearwardly away from said cartridge chamber end by the explosive forceof a fired cartridge;

(e) a distinct compensating mass member operable only to stabilize thefire-arm, said distinct compensating mass member being movable in a pathparallel to said barrel between two end positions, said compensatingmass member having a mass corresponding substantially to the mass ofsaid breech block;

(f) a return spring cooperating with said compensating mass member andurging the latter on said path toward one of said end positions; and,

(g) means for imparting to said compensating mass member a movementdirected toward said forward position corresponding substantially to themovement imparted to said breech block by the explosive force of a firedcartridge and substantially concurrent therewith to thereby reduce therecoil.

2. A fire-arm as claimed in claim 1, wherein said compensating massmember is in the form of a piston.

3. A fire-arm as claimed in claim 2, further including a cylinderattached to said frame and containing said piston slidably arrangedtherein, said transmission means comprising a bleed channelinterconnecting said barrel with said cylinder, said return spring beingarranged in said cylinder.

4. A fire-arm as claimed in claim 3, wherein said bleed channelterminates in a bleed bore communicating with the bore of said barreladjacent said cartridge chamber end thereof.

5. A fire-arm as claimed in claim 2, wherein said piston is formed by anannular member surrounding said barrel and slidable thereon, said memberhaving gas chamber means formed therein, said transmission meanscommunicating with said gas chamber, said return spring surrounding saidbarrel.

6. A fire-arm as claimed in claim 5, wherein said gas chamber meanscmoprises a plurality of axially extending bores, and wherein saidtransmission means include stationary axially extending tubes extendinginto said bores ad communicating with bleed openings provided in saidbarrel. 1

7. A fire-arm as claimed in claim 1, wherein said transmission meansinterconnect said compensating mass member with said breech block.

8. A fire-arm as claimed in claim 7, wherein said compensating massmember is formed by a slide.

9. A fire-arm as claimed in claim 7, said transmission means comprisinga first tooth rack on said breech block, a second tooth rack on saidcompensating mass member and gear means meshing with said first andsecond tooth rack and supported for rotation by said frame.

10. In a fire-arm having a frame, a barrel supported by said frame andhaving a cartridge chamber end, a breech block arranged for reciprocablemovement towards and away from said cartridge chamber end of saidbarrel, a recoil spring cooperating with said breech block for urgingthe latter toward said cartridge chamber end, said breech block beingdriven away from said cartridge chamber end by the explosive force of afired cartridge, the improvement comprising a distinct compensating massmember operable only to stabilize the fire-arm, said distinctcompensating mass member being movable in a path substantially parallelto said barrel between a rearward position and a forward position, saidcompensating mass member having a mass corresponding substantially tothe mass of said breech block, means for imparting to said compensatingmass member a movement directed toward said forward position tosubstantially counteract the recoil effect of said breech block whendriven away from said cartridge chamber end.

References Cited UNITED STATES PATENTS 891,778 6/1908 Mertens 891.7 X1,786,207 12/1930 Hudson 89-191 X 3,273,460 9/1966 Mason 89-191 X827,259 7/1906 McClean 89l28 2,940,202 6/1960 Harper 89-l94 X 3,208,3489/1965 Lee 8914.3

SAMUEL W. ENGLE, Primary Examiner U.S. Cl. X.R. 89-14, 42, 196

